Invention relates to search engine interfaces, particularly search engine interfaces in network data processors.
Traditionally, the search function in network packet processors has been an integral part of the packet processing, either implemented via software or via direct access of pattern matching lookup tables stored on a RAM, or a content addressable memory (CAM). There is no conventional interface between a header data processing and the critical search function processing comprising header data lookup and processing in ATM or Internet Protocol (IP), or in other network protocols such as an ethernet, and custom protocols.
With increasing ternary CAMs and fast SRAMs developed with its own associated proprietary CAM or SRAM interface, as well as unique search algorithms being increasingly performed by dedicated processing elements, the search function is correspondingly a non-integral part of packet processing. There is therefore a need for a flexible search engine interface and a protocol that functions as an adaptor, or a communication vehicle between the internet data processor and a search engine.
A search engine interface system is provided comprising a header analyzer, which receives incoming network data stream, such as from the internet or ATM network, and parses up that incoming data packet (or ATM cell, if ATM application) to identify the header information. Header parser is then coupled to a search engine interface adaptor that receives from header parser via a search engine interface bus output data signals comprising, such as, for example, a 32-bit data word 13, Data_Out [31 . . . 0], together with a data valid flag signal 15 (Dvalid_Out ), and a command valid flag signal 17 (Cvalid_Out). In response to receiving a search command identified via the search engine interface bus, search engine interface adaptor also generates an output memory store search request provided to a memory storage, such as a ternary CAM, or alternatively to a SRAM, for pattern matching. Results of search from a memory storage CAM or SRAM are then provided back to search engine adaptor, which then conveys the search response via search response signals, such as via search engine interface bus data word Data_In[31 . . . 0] and valid response flag signal, Valid_In, back to header analyzer.